Deep well pump jack



Oct. 1965 c. J. scoeems, JR

DEEP WELL PUMP JACK 2 Sheets-Sheet 1 Filed June 27, 1963 TIE-.1.

INVENTOR.

BY FHA/057.1% 0 (76m n ,4 7' 7' 0NFYS Oct. 5, 1965 c. J. scoeems, JR

DEEP WELL PUMP JACK 2 Sheets-Sheet 2 Filed June 27, 1965 FJ E-Z INVENTOR.

BYCLA U D E flaw/fly,

United States Patent 3,209,605 DEEP WELL PUMP JACK Claude J. Scoggins, Jr., 5412 N. Terry St., Oklahoma City, Okla. Filed June 27, 1963, Ser. No. 291,152 6 Claims. (Cl. 74-48) This invention relates to deep well pumps of the type used to recover subterranean oil deposits and, more particularly, to deep well pumps of the type in which the pumping motion is originated at the surface of the ground and transmitted through a reciprocating string of rods to a pump located within the well bore. Yet more particularly, but not by way of limitation, the present invention is especially concerned with an improvement in the efficiency with which the fluid and mechanical loads imposed upon a pumping unit of the type described may be counterbalanced.

In deep well pumps, such as oil well pumps, of the type in which the pumping motion of the subsurface pumping equipment originates at the surface of the ground (as opposed to subsurface pumps in which the pumping motion originates below the surface of the ground as a result of the supply of power fluid to the subsurface pump), effective counterbalancing of the pumping unit to reduce the load on the prime mover and power translating equipment is extremely important. In conventional oil well sucker rod pumps, it has been estimated that about 90 jpercent of the failures of speed of reduction gearing, pitmans, bearings and shafts result from improper counterbalancing. The primary purpose in counterbalancing a pumping unit is to reduce the effective peak load on the prime mover and gear box through which the prime mover drives the unit so that smaller engines and less massive speed reduction gearing can be employed. This in turn results in an economic saving since it is less expensive to supply counterbalancing weights than it is to provide the heavier, more complicated engines and gear reduction systems necessary to drive the pumping unit without the assistance of effective counterbalancing. In an ideally counterbalanced system, the total load imposed upon the pumping unit by the fluid load lifted by the pump, plus the weight of the rods and losses due to friction, etc., would be substantially completely oflset by a counterbalance applying an opposing force to the motor. However, the systems heretofore most widely used have at best been effective to counterbalance a downwardly acting force equal to the weight of the rods used to pump the liquid, plus one-half of the weight of the fluid lifted by the pump. Under this arrangement, the net load lifted during the upstroke of the pump equals the load applied to the pump through the sucker rod string less the countereffect of the counterbalance. Since, during the upstroke, the static load on the pumping equipment consists essentially of the weight of the rods plus the weight of the fluid, the net load on the system when the counterbalance effect is subtracted equals half of the weight of the fluid lifted. On the downstroke, on the other hand, the net load equals the counterbalance weight less the weight of the falling rods, or again, approximately half the weight of the fluid lifted on the upstroke. The net load on the prime mover and gear box is therefore equal during the upstroke and the downstroke. Moreover, the peak load occurring during each stroke is considerably less (by the amount of approximately half the weight of the fluid load) than the peak load imposed on the unit through the sucker rod string without benefit of any counterbalancing. In terms of the peak torque applied to the drive shaft of the speed reduction gearing normally used, the peak torque may be reduced by as much as about 40 percent when proper counterbalancing 3,209,605 Patented Oct. 5, 1965 "Ice is used in the conventional deep well sucker rod pumping unit of the type in which the prime mover and gear box are located on the ground and a pitman crank and walking beam are used to translate the rotary movement of the primer mover into the reciprocating movement of the sucker rod string.

For a number of years, efforts have been directed to the more effective counterbalancing of the torque imposed on the prime mover and gear reducer of deep well pumps of the type described. Generally, however, such efforts, while in some instances being effective to reduce the peak torque transmitted to the driving mechanism from the rod string, have increased the cost of the pumping unit to the extent that an improvement in counterbalancing over that which is most widely currently attained has not been found to be economically justified.

One of the earlier efforts to depart from the conventional counterbalancing techniques, and to improve the degree to which the load on the pumping unit might be effectively counterbalanced was that of Calvin I. Thomas described in United States Patent 2,184,200. In the Thomas system, a pair of counterrotating weights were mounted on the walking beam of a conventional sucker rod oil well pump and were driven in counterrotation by a motor mounted on the beam and working through a gear box. Both the motor and gear box were secured on the beam and maintained at a fixed distance from the axis of oscillation of the beam. The Thomas structure, however, provided a hazard to operating personnel as a result of the counterrotating weights used for counterbalancing, and also lacked convenient adjustability in the length of the pump stroke.

A more recent effort to more effectively counterbalance the well load suspended from the walking beam is disclosed and described in Downing United States Patent 2,432,735. In the Downing patent, a counterweight is slidably mounted on the walking beam and is shifted by a hydraulic cylinder carried by the walking beam in a properly timed sequence to counterbalance the well load. The system, however, still required a separate prime mover and gear reduction system for driving the walking beam in an oscillating movement which was synchronized with the activation -of the weight shifting hydraulic cylinder.

Two other recent efforts at improving counterbalancing effect by mounting a shifting weight upon the walking beam of the pump or by changing the moment of the counterweight are described in C. C. Mitchell United States Patents 2,940,335 and 2,995,048 and J. Chastain United States Patent 2,841,992. The Chastain system in particular claims to go far towards reducing the peak load imposed on the prime mover and speed reducer during both the upstroke and downstroke as a result of changing the effective moment of the counterbalance by changing the leverage of the counterweight as it is applied to a crank arm connected directly to the speed reducer. However, the Chastain system requires the provision of a plaform for supportingthe prime mover and gear reducer above the ground, and, in addition, requires the employment of several crank arms and levers not required in conventional pumping units.

It is proposed by the present invention to provide an improved counterbalancing system in which the total cost of the pumping unit is reduced as a result of a reduction. in the total counterbalancing weight required to effectively counterbalance well loads of the type normally encountered. Moreover, with a smaller counterbalancing weight, a greater portion of the well load may be counterbalanced in a manner which is effective to reduce the peak torque which the prime mover and speed reducer must overcome during the pumping cycle, both on the upstroke and downstroke of the pump.

Broadly, the present invention comprises a reciprocating well pump of the type having the reciprocating pumping motion originating at the surface of the ground and including an oscillating walking beam, a string of rods depending from one end of the walking beam and reciprocated thereby in the bore of the well for operating a pump unit disposed in the well, a counterbalancing weight vreciprocable mounted on the walking beam on the opposite side of its axis of oscillation from the point of attachment of the rod string, and means for moving the counterbalancing weight in a generally circular path to thereby impart an oscillating motion to the walking beam which supports the counterbalancing weight. More specifically, in one of its forms the present invention comprises a conventional reciprocating well pump of the type including a walking beam and sucker rod string, in which pump a counterbalancing weight is slidably mounted on the walking beam for reciprocating movement therealong toward and away from the axis of oscillation of the beam and in which the counterbalancing weight is driven in a generally circular motion by a prime mover acting through a crank arm which is pivotally connected at one of its ends to the counterbalancing weight and at its other end to a rigid member which is fixed in its position relative to the ground and to the axis of oscillation of the walking beam.

In one embodiment of the invention, the prime mover and gear reduction box are mounted on the walking beam of the pump and are continuously shifted along the walking beam in a reciprocating movement toward and away from the axis of oscillation of the walking beam. The reciprocating motion of the prime mover and .speed reducing apparatus, and also the oscillation of the walking beam are effected by a common crank which is pivotally journaled at one of its ends to a vertical standard or rigid upright member. It will be perceived that in mounting the prime mover and speed reducing mechanism on the walking beam, and by shifting these elements of the pump along the walking beam in a properly timed reciprocating motion, the counterbalance weight which would otherwise be normally mounted in a fixed position on the walking beam or secured to the shaft of the gear reducing apparatus is eliminated and a large amount of weight and apparatus thereby saved. The initial cost and maintenance cost of the pump are reduced accordingly.

Accordingly, it is an object of the present invention to substantially reduce or eliminate the mass of material which has heretofore been employed as a counterbalance in the most widely used and conventional oil well sucker .rod pumps.

A further object of the invention is to improve the efficiency with which the well load imposed upon a sucker rod type oil well pump may be counterbalanced during all portions of the pump stroke.

Afurther object of the invention is to provide a deep well pump jack in which the prime mover and speed reduction mechanism used to drive the pump are mounted on the walking beam thereof so as to permit a less cluttered working area on the ground around and under the pump.

A further object of the present invention is to provide a deep well pump of the type having an oscillating walking beam and sucker rod string in which the prime mover and speed reduction mechanism of the pump are mounted on the walking beam and oscillate therewith so that better lubrication of the working parts of the prime mover and gear reduction mechanism may be obtained by splash and gravity lubrication.

Another object of the present invention is to provide a reciprocating deep well pump of the type having an oscillating walking beam and reciprocating sucker rod string in which the reciprocation of the rod spring is accelerated at a faster rate on the downstroke of the pump than on the upstroke so that the peak well load on the 4 upstroke and downstroke of the pump are more nearly balanced and the peak well loads acting on both the up and downstroke are reduced.

An additional object of the present invention is to provide a pump assembly of the type having a walking beam and a string of pump rods attached to one end of the walking beam for reciprocation in the well bore, in which the pump assembly well load transmitted through the string of rods during the operation of the pump is from to percent counterbalanced during both the up and downstroke of the pump.

An additional object of the present invention is to provide a pumping jack assembly for use in sucker rod pumps, which assembly may be relatively inexpensively constructed and which is characterized by a relatively long and trouble-free operating llife, primarily as the result of more effective counterbalancing of the Well load.

Additional objects and advantages will become apparent from the following detailed description of the invention when considered in conjunction with a perusal of the accompanying drawings which illustrate the invention.

In the drawings:

FIGURE 1 is a view in elevation of one embodiment of a well pump constructed in accordance with the present invention.

FIGURE 2 is a plan view of the embodiment of the invention illustrated in FIGURE 1.

FIGURE 2a is a diagram illustrating the movements of various elements of the well pump of the present invention.

FIGURE 3 is a view in elevation of a well pump constructed in accordance with the teaching of the present invention, but constituting a different embodiment of the invention from that shown in FIGURE 1.

FIGURE 4 is a plan view of the well pump illustrated in FIGURE 3. 1

FIGURE 5 is a sectional view taken along line 5-5 of FIGURE 3.

Referring now to the drawings in detail, and particularly, to FIGURE 1, the embodiment of a well pump jack constructed in accordance with the present invention illustrated in FIGURE 1 comprises a conventional Samson post 10 of one of the types well-recognized and widely used in the art. The Samson post rests upon and projects upwardly from a suitable sub-structure or support slab 12 which in turn rests upon the surface of the ground adjacent a well bore (not seen). An elongated walking beam 14 is secured to a saddle 16 positioned intermediate the length of the walking beam, and the saddle 16 is pivotally supported upon the upper end of the Samson post 10. The walking beam 14 carries at its end adjacent the well bore, a horsehead or mulehead 18 which is positioned in approximate vertical alignment with the well bore. A wire line 20 is attached to the mulehead 18 at the upper end thereof, and the wire line 20 is connected through a rod clamp seat 22 to the polished rod 24 which constitutes the uppermost rod in a string of sucker rods extending downwardly into the well bore. The polished rod 24 passes through a pumping T 26, or similar fitting, into the production tubing (not shown) which is positioned in the well bore. The portion of the pumping apparatus which has thus far been described will be recognized by those skilled in the art as conventional and widely used for producing petroleum from subterranean deposits.

In accordance with the teaching of the present invention, a pair of parallel track members 30 are provided on the upper side of the walking beam 14 and extend from a point adjacent one end thereof to a point above the saddle 16. The tracks 30 support and engage the wheels 32 of a drive assembly designated generally by reference character 34, which assembly includes a prime mover 36 and suitable speed reduction gearing 38. In one embodiment of the invention, both the prime mover 36 and speed reduction gearing 38 are mounted upon a common bed or frame 40 which is supported by the wheels 32 for rolling movement along the tracks 30. A pair of retaining brackets 41 extend downwardly from each end of the bed 40 to engage the tracks 30. The prime mover 36 is connected to the speed reduction gearing 38 by a suitable drive shaft 42, and an output shaft 44 extends from the speed reduction gearing 38 normal to the longitudinal axis of the Walking beam 14. The prime mover 36 may be of any suitable type, such as an electric motor, or, as illustrated in FIGURE 1, a gasoline engine. The power developed by the prime mover is transmitted through the shaft 42 into the speed reduction gearing 38 and is employed to drive the shaft 44 in rotation at a desired pumping speed.

In the embodiment illustrated in FIGURE 1, the rotational movement of the shaft 44 is translated into an oscillating motion of the walking beam 14 by means of a pitman assembly designated generally by reference character. 50. The pitman assembly 50 includes a vertically extending rigid support member 52 which is fixed in its position relative to the ground, and may conveniently be bolted or otherwise suitably secured to the Sampson post 10. The rigid support member 52 includes an arm 54 to which is pivotally journaled at one of its ends a crank 56. The opposite end of the crank 56 is secured or keyed to the shaft 44 for rotation therewith.

In the operation of the well pump assembly illustrated in FIGURES 1 and 2, when the prime mover 34 is energized, the shaft 44 is driven in rotation so that the crank 56 is caused to rotate about the axis of this shaft. As the crank 56 rotates with the shaft 44, it pivots about its .pivotal axis extending through the point at which it is rotatably journaled to the member 54 of rigid support member 52. The net result of these movements is that the assembly 34 is caused to move in a generally circular movement with the shaft 44 describing a circle having a radius equivalent to the length of the crank 56 and having its center at the point of attachment of the crank 56 to the rigid support member 52.

The generally circular movement of the prime moverspeed reduction gearing assembly 34 results in an oscillating movement being imparted to the walking beam 14, and a simultaneous reciprocating movement the prime mover 36 and speed reduction gearing 38 along the walking beam toward and away from the axis of oscillation of the beam at the saddle 16. The motion of the prime mover-speed reduction gearing assembly 34 on the walking beam 14 is such that the assembly 34 is moved inwardly toward the axis of oscillation of the walking beam 14 during the latter portion of the upstroke and the initial portion of the downstroke so that the smallest moment opposing the well load and acting about the axis of oscillation of the walking beam occurs during the downstroke of the pump at such time as the pump is not loaded with fluid being carried to the surface. On the other hand, about one-third of the way through the downstroke, the direction of movement of the prime mover-speed reduction gearing assembly 34 is reversed and the assembly moves outwardly toward the free end of the walking beam 14 and away from the axis of oscillation of the beam. The point of farthest removal from the axis of oscillation of the walking beam 14 of the prime mover-speed reduction gearing 34 occurs at a point .in time which is about one-third of the way through the upstroke of the pump so that the maximum counterbalancing effect is obtained at thist time. It will be recog- :FIGURES 1 and 2 as thus far described, it will be perceived that two major advantages accrue from the proposed construction. First, in mounting the prime mover 36 and speed reduction gearing 38 on the walking beam 14, the necessity to provide a large stationary counterbalancing weight on the Walking beam or on the drive shaft of the speed reduction gearing, as is now frequent- 1y done, is obviated and the cost of such counterbalancing weight is eliminated. Moreover, the area beneath the walking beam is less cluttered with operating apparatus and more freedom of movement is available to operating personnel. The second major advantage of the construction illustrated in FIGURES 1 and 2 is that the prime mover 36 and speed reduction gearing 38 may be caused to shift on the walking beam 14 in a manner which effectively reduces or increases the distance of the mass constituted by these elements from the axis of oscillation of the beam at times when it is desirable to increase or decrease the effective counterbalancing moment due to a corresponding increase or decrease in the well load imposed on the pumping assembly.

A further advantage of the pumping assembly illustrated in FIGURES 1 and 2 accrues from the fact that the pumping stroke of the pump undergoes greater acceleration on the downstroke of the pump than on the upstroke thereof. As will be appreciated by those skilled in the art, an increase in acceleration on the downstroke lowers the effective weight imposed upon the pumping assembly by the string of sucker rods and results in a corresponding decrease in opposing torque transmitted to the speed reduction gearing as a result of the total acting Well load. The opposite effect is encountered on the upstroke where a decrease in acceleration effectively lowers the well load, and results in a corresponding decrease in negative torque acting in oposition to the positive torque transmitted to the speed reduction gearing from the prime mover.

The explanation for the increased acceleration pro vided on the downstroke and the decrease in acceleration which occurs on the upstroke of the pumping assembly illustrated in FIGURES 1 and 2 may be more easily perceived when reference is made to FIGURE 2a of the drawings. In this figure, the motion of the prime mover 36 and speed reduction gearing 38 may, for purposes of explanation, be generally described as an approximate circle having a radius equal to the length of the crank 56, and having its center at the point of attachment of the crank 56 to the rigid support member 52. The walking beam 14 may be thought of as a line extending tan.- gentially to the circle with the points of tangency occurring at the point in the pumping cycle at which stroke reversal occurs. It may be seen that when the direction of rotation of shaft 44 is such as to cause the prime mover 36 and speed reduction gearing 38 to move counterclockwise around the circle as these elements are viewed in FIGURES 1 and 2, the upstroke of the pumping assembly occurs over aproximately 200 of the entire 360 in the circle, while the downstroke occurs only over of the circle. Since the shaft 44 is driven at a constant rate of speed, the rate of movement of the prime mover 36 and speed reduction gearing 38 in their circular orbit must also occur at constant speed. It follows then that the oscillating movement of the walking beam 14 must occur more rapidly during the downstroke than duri-ng the upstroke since both strokes must necessarily be of equal length. In order to accomplish the downstroke in less time, it is, of course, necessary that the string of rods be accelerated downwardly in the well at a faster rate than the string is accelerated upwardly during the upstroke.

In passing, it should be noted that the theoretical movements represented by the FIGURE 2a diagram do not actually occur in an assembly of the precise type ilustrated in FIGURES 1 and 2 in that the longitudinal axis of the walking beam 14 is not at any time precisely tangent to the circle defined by the movement of the shaft 44. Rather, a distorted elliptical figure is swept out by the center of gravity of the prime mover 36 and 38 as this point is translated into the plane of the longitudinal axis of the walking beam, and it is with respect to this distorted elliptical figure that the longitudinal axis of the walking beam is tangent during the pumping cycle.

It is our present belief that some advantage is obtained by having the drive shaft 44 spaced vertically from the longitudinal axis of the walking beam 14 by a short distance so as to result in this distorted elliptical movement of the center of gravity although We have not been able to date to reduce the optimum dimensions and spatial relationships to a mathmatical formula which can be applied in the case of every pumping rig. In general, however, some general statements may be made regarding the effect of changing the relative locations and dimensions of some of the operating elements illustrated in the FIGURES l and 2 assembly. Thus, it will be apparent in referring to FIGURE 2a that by shifting the point of connection of the crank 56 with the rigid support means 52 toward the axis of oscillation of the walking beam 14, the increment of time over which the downstroke is accomplished will be made shorter relative to the increment of time over which the upstroke is accomplished. In other words, a greater rate of acceleration will occur on the downstroke of the pump if the point of connection of the crank 56 to the rigid support member 52 is moved toward the axis of oscillation of the walking beam 14 without changing the length of the crank 56. It is to be recalled, however, that in shifting the point of connection of the crank 56 to the rigid support member 52 toward the axis of oscillation of the walking beam 14, the effective moment about the axis of oscillation resulting from the counterbalancing weight of the prime mover 34 and the speed reduction gearing 38 is reduced so that less counterbalancing moment is developed both on the upstroke and on the downstroke. It is therefore usually necessary to compensate for the shift in the assembly toward the axis of oscillation by increasing the size of the prime mover 36 and speed reduction gearing 38, or by adding counterweight to the moving assembly in some other form to compensate for the reduction in the lever arm acting between these elements and the axis of oscillation of the walking beam.

It will also be apparent in referring to FIGURES 1 through 2a that the length of both the up and down strokes of the pump assembly is determined by the length of the crank 56. Thus, a preferred embodiment of the invention contemplates the use of a crank of adjustable length.

Another effect of changing the length of the crank 56 is to change the relative accelerations occurring on the upstroke and the downstroke of the pump. Thus, as the circle shown in FIGURE 2a of the drawings becomes larger by increasing the size of its radius, the points of tangency of the walking beam longitudinal axis to such circle move toward each other in a direction to reduce the time consumed on the downstroke and increase the time consumed on the upstroke.

Moving the prime mover 36 and speed reduction gearing 38 outwardly toward the free end of the walking beam 14 and away from the axis of oscillation of the beam changes the applied leverage resulting from the counterbalancing eifect of these elements so that heavier rod strings and/or heavier well loads may be counterbalanced as in the case, for example, of deeper wells. However, this movement of the prime mover 36 and speed reduction gearing 38 also shortens the length of the stroke of the pump and decreases the differences between the accelerations occurring on the upstroke and downstroke.

A different embodiment of the well pump assembly of the present invention is illustrated in FIGURES 3, 4 and 5. This embodiment of the invention is particularly useful where it is for any reason desirable to maintain the prime mover and speed reduction gearing at ground level rather than mounting these elements on the walking beam. In the illustration of the embodiment of the invention depicted in FIGURES 3, 4 and 5, identical reference numerals have been employed to designate the parts of the assembly which are identical to the corresponding parts of the embodiment illustrated in FIGURES 1 and 2. The prime mover 36 and speed reduction gearing 38 are supported on the sub-structure 12 and the drive between the prime mover and speed reduction gearing is effected by a suitable belt or chain 60. Positioned on each side of the speed reduction gearing 38 and extending upwardly on opposite sides of the walking beam 14 are a pair of vertically upright standards or rigid support members 62. At its upper end, each of the rigid support members 62 rotatably journals one end of a generally S-shaped crank 66 which is rotatably journaled at its other end in a counterbalancing weight 68 slidably mounted on the walking beam 14. As will be perceived in referring to FIGURE 5 of the drawings, the counterbalancing weight 68 is generally rectangular in vertical cross section and is provided with an opening therethrough which slidably receives the walking beam 14. Suitable bearings 70 are provided on each side of the walking beam 14 between the beam and the enclosing walls of the counterbalancing weight 68.

For the purpose of rotating the counterbalancing weight 68 and oscillating the walking beam 14, a suitable driving belt or chain 72 is connected between the output shaft 74 of the speed reduction gearing 38 and the legs of the S- shaped cranks 66 which are journaled in the rigid support members 62. The rotation of these legs of the cranks 66 cause the counterbalancing weight 68 to move in a circular motion about the pivotal axis of the cranks 66 in the rigid support members 62. The revolving movement of the counterbalancing weight 68 causes the walking beam 14 to be oscillated in substantially the same manner as hereinbefore described. The counterbalancing effect of the weight 68 occurs in the same way as the counterbalancing effect arises from the movement of the prime mover 36 and speed reduction gearing 38 when these elements are reciprocably mounted on the walking beam 14 as shown in FIGURES 1 and 2.

An advantage of the embodiment of the invention illustrated in FIGURES 3, 4 and 5 over that illustrated in FIGURES l and 2 is that the prime mover 36 and speed reduction gearing 38, in being located on the sub-structure 12, are more accessible for maintenance, replenishment of lubricant, etc. On the other hand, it will be perceived that the additional expense of providing the massive counterweight 68 in addition to the prime mover 36 and speed reduction gearing 38 is encountered in using the FIGURE 3 through 5 embodiment, and that the additional expense resulting from the required provision of such additional weight is obviatedin the FIGURE 1 and 2 embodiment.

From the foregoing description of the invention, it will be perceived that the pump assembly here proposed more effectively counterbalances the well loads imposed on a reciprocating pumping assembly located at the surface of the ground than the type of counterbalancing methods heretofore employed. Moreover, the assembly may be more economically constructed and is characterized by fewer moving parts and a smaller required amount of counterbalancing weight than has been characteristic of previous assemblies. It is recognized and appreciated that those skilled in the art may perceive certain changes which may be beneficially made in the form, details, arrangement and proportion of the various parts of the assembly hereinbefore described. It is to be borne in mind, however, that the described assemblies constitute but two embodiments of the invention which are herein described by way of example only. Therefore, all changes and modifications in the specific structures herein described which do not entail a departure from the employment of the basic principles underlying the invention are deemed to be circumscribed by the spirit and scope of the invention except as the same may be necessarily limited by the language of the appended claims or reasonable equivalents beam toward and away from the axis of oscillation thereof. of said beam;

What is claimed is: (15) speed reduction gearing drivingly connected to said 1. In a reciprocating well pump assembly of the type prime mover and reciprocably mounted on said walkhaving the pumping motion originating at the surface of ing beam for movement with said prime mover tothe ground, ward and away from the axis of oscillation of said (a) a walking beam; (b) means supporting the walking beam vertically spaced from the ground for oscillation in a substanbea-m,'said gear box including a driven shaft extending normal to the longitudinal axis of said walking beam; and

tially vertical plane; g) an assembly connected to said prime mover through -(c) a string of sucker rods connected to one end of said gear box and having a rigid member fixed relasaid walking beam for reciprocation in a well bore tive to the ground and a crank anm pivotally conby the oscillating motion of the walking beam; nected at one of its ends to said rigid member and (d) a pump unit in the well and connected to said secured at its other end to said driven shaft for rotastring of sucker rods; tion with said shaft whereby said shaft is revolved (e) a prime mover movably mounted on said walking about the axis of pivotation of said crank arm at its beam for reciprocating movement along said walking point of connection with said rigid member and is beam toward and away from the axis of oscillation reciprocated on said walking beam. of said beam, said prime mover constituting a counter- 4. A reciprocating well pump assembly as claimed in balancing weight; and claim 3 wherein said driven shaft is spaced vertically (i) an assembly connected to said counterbalancing weight and including rigid support means fixed relative to the ground, crank means pivotally connected to said rigid support means, and power transmission from the longitudinal axis of said walking beam.

5. A reciprocating well pump assembly as claimed in claim 3 wherein said supporting means comprises:

(a) a vertically extending Samson post; and

means connected between said prime mover and said (b) a saddle cradling said walking beam intermediate crank means, said Prime mover being rotated ut its length and pivotally supported on said Samson the pivotal axis of said crank means at its connection post, and wherein said rigid member is secured to, with said rigid member and reciprocating on said and supported by, said Samson post.

walking beam during said revolving movement when 6. In a reciprocating well pump assembly of the type said prime mover is energized. having the pumping motion originating 'at the surface of 2. In a reciprocating well pump assembly of the type having the pumping motion originating at the surface of the ground,

the ground,

(a) a walking beam; (b) means supporting the walking beam vertically (a) a walking beam;

spaced from the ground for oscillation in a substan- (b) track means on said walking beam and extending tially vertical plane;

parallel to the longitudinal axis thereof; (0) a string of sucker rods connected to one end of said means Supporting the Walking beam Vertically walking beam for reciprocation in a well bore by the spaced from the ground for oscillation in a substanoscillating motion of the walking beam; tially vertical plane; (d) a pump unit in the well and connected to said (d) a string of sucker rods connected to one end of 40 string f sueker ds;

said walking beam for reciprocation in a well bore by (e) an apertured block constituting a counterbalacing the oscillating motion of the walking beam; weight, and slidingly receiving said walking beam a P p 1111K 1n the W611 and connected to Sflld through said aperture for reciprocating movement string of sucker rods; along said walking beam toward and away from the (f) a counterbalancing prime mover movably mounted axis of oscillation of said walking beam;

on said walking beam for reciprocating movement on (f) bearing means interposed between the upper sur- Sflid Walking b63111 toward and y from e aXiS face of said walking beam and said apertured block of oscillation of the walking bea Sa d p i moveg and contacting said walking beam and said apertured having wheels supporting said prime mover on sai bl k; track means; and b (g) second bearing means interposed between the lower (5;) an assgmbly Connected to Said counteralanclng surface of said walking beam and said apertured Prime mover and incllding li PP Q 1 1 fixed block and contacting the lower surface of said walkrelative to the groun cran means pivota y coning beam n said apertured block; nected Said rigid PP an Output (h) rigid support means fixed relative to the ground; Shaft dfivingly 9nnected t0 531d P Q Q (i) a pair of horizontally spaced crank arms extending connectebdl to said crank means for fi gg ga upiwardfly frgm slid mild suppodrthmeans 0T1 OPPOSltZ Counter a anclng P mover 111 Tel/O u 1 I1 si es 0 sai wa ing earn an orizonta y space the pivotal axis of said crank means at its connectioln th f Said crank arms being i u connected Wi h Said rigid po Imam and Simultaneous Y to said rigid support means at one of their ends, and reciprocal-ing Said countefbalancing Prime member on connected to opposite sides of said apertured block 3 sIaid walking beta m. 11 um assembly of the type at) the Ether of ltheir eids flor if'evolging slaid block n a fi p lIlg We P P a outt e p vota axis 0 eac o sai cran arms at having the pumping motion Orlgmatlng at the Surface of its pivotal connection with said rigid support means, the ground, and for reciprocating said apertured block on said (a) a Walking beam; walking beam during said revolving movement; means Supporting the Walking beam in Y f (j) a prime mover supported on the ground below the spaced relation t0 the ground for OSClHatlOIl 111 a vertical level of said walking beam; substantially vertical plane; d (k) speed reductiordi glearing drivinglybtionflie cted to said (c) a string of sucker rods flexibly connecte to one prmre mover an aving a rotata y riven outpu end of said walking beam for reciprocation in said shaft; and well by the oscillatory motion of said beam; means g y connectmg said Speed reductwn (d) a pump unit in the well and connected to said g g to said crank arms for o g string of sucker rods; I armds about their respective pivotal connection to said (e) a prime mover reciprocably mounted on said walk- Support meansing beam for reciprocating movement along said (References on following page) Boicourt 74--108 X Baker 7441 McCrosky 74-41 Jones 7441 Porter 74103 Humphrey 7445 Fuller 7448 Porter 7441 Holzer 74103 Anderson 7441 De La Mater 7441 Fullerton 74-41 BROUGHTON G. DURHAM, Primary Examiner.

MILTON KAUFMAN, Examiner. 

1. IN A RECIPROCATING WELL PUMP ASSEMBLY OF THE TYPE HAVING THE PUMPING MOTION ORIGINATING AT THE SURFACE OF THE GROUND, (A) A WALKING BEAM; (B) MEANS SUPPORTING THE WALKING BEAM VERTICALLY SPACED FROM THE GROUND FOR OSCILLATION IN A SUBSTANTIALLY VERTICAL PLANE; (C) A STRING OF SUCKER RODS CONNECTED TO ONE END OF SAID WALKING BEAM FOR RECIPROCATION IN A WELL BORE BY THE OSCILLATING MOTION OF THE WALKING BEAM; (D) A PUMP UNIT IN THE WELL AND CONNECTED TO SAID STRING OF SUCKER RODS; (E) A PRIME MOVER MOVABLY MOUNTED ON SAID WALKING BEAM FOR RECIPROCATING MOVEMENT ALONG SAID WALKING BEAM TOWARD AND AWAY FROM THE AXIS OF OSCILLATION OF SAID BEAM, SAID PRIME MOVER CONSTITUTING A COUNTERBALANCING WEIGHT; AND 